X-ray apparatus.



H. F. WAITE. X-RAY APPARATUS. APPLICATION FILED FEB. 1a. x913.

Patented A r. 27', 1915.

2 SHEETS-SHEET la ike anew.

H. F. WAI TE x-RAY APPARATUS. MFQJCATION FILED FEB. 18, 1913.

Patented Apr. 27, 1915.

2 SH RTS-SHEET 2.

Svwemtoz Waite;

HARRY r. WAITE, or NEW YORK, n. Y.

,X-RAY APPARATUS.

. s I Specification of Letters Patent. Patented Apr. 27, 1915.

Application filed Fbruary 18, 1913. Serial No, 749,200.

To allwhom it may concern f Be it known that I, HARRY F, WAITE, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful -Improvements in X-Ray Apparatus; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art'to which it appertains to make and use the same.

. This invention relates to improvements in- X-ray apparatus, and has for its obj'ectto provide a simple, efficlent and inexpensive means by which an alternating current of a Y given frequency may be so controlled as to have the effect in an X-ray tube of one or more currents of less frequency.

To these ends the invention consists in the novel details of construction and combinations of parts more fully hereinafter disclosed and particularly pointed out in the.

claims,

Referring to the accompanying drawings forming a part of this specification in which like numerals designate like parts in all the views-Figure 1 is a diagrammatic view illustrating a mechanism suitable for carrying out my invention; Fig. 2 is a side elevational view partly in section of a synchronous motor suitable for furnishing the current to the X-ray tube; Fig. 3 is a diagrammatic side elevational view of switch apparatus employed in connection Vwith the motor generator shown in Fig. 2,

and showing the conducting segment in one position; and Fig. 4 is a view similar to Fig. 3, showing the conducting segment in another position.

Referring to the drawings :1 indicates a primary of a high tension step-up transformer which m y be conveniently connectedv in parallel w'th a synchronous motor, such as 2, joined in. the leads 3 of any suitable source of alternating current supply, for example an alternating current generator or inverted rotary, such as 4, and 5 indicates a suitable rheostat conveniently placed in series with the transformer primary. I

, Upon the shaft 6 of the motor 2,,I mount the disk 7 of insulating material, to which is attached the conducting half ring 8 extending 180, around the circumference of said disk 7, and in operative relation with said conducting member 8, I mount the three a rotary holders are also provided with the spring:

members 19, 20 and 21, as shown, which .press against the carbon contacts 22, 23

and 24. r

The X-ray tube to be operated is designated at '30, and from this tube lead the wires 31 and 32 to the secondary 33 as in my prior Patent 1,061,428, dated May 13, 1913, and entitled X-ray system. The shaft 35 is an extension of the shaft 6, and the rectifier members 36, 36 and 38 are the same as in said patent.

The operation of my present invention will be clear fromthe following :Suppose a current of say cycles per second is passed through the primary coil 1, a wave will pass from one end of said coil along the lead wire 16 to the binding post 13, along the holder 9 to the carbon contact 22,'to the conducting segment or ring 8, along-said segment to the carbon contact 23, through the holder 10, and the wire 17 rheostat 5, and lead 3 back to the source 4 of the current. Upon starting the machine the disk should be so adjusted that the segment or conducting element 8 will break connection with the contact members such as 22, 23 and. 24, when the electromotive force of the current wave is zero. Upon said segment and disk being now rotated in the direction of the arrow at a speed of 30 revolutions per second at each revolution during the quarter turn that contact is made with said segment by both of the contacts 22 and 23 a halfwave will pass from the contact 22 along said segment 8 and out of the contact 23, while the succeedin three half waves will be cut out during t e remaining three quarters of the same turn. The result of this is that only 30 half waves of the 60. cycles of the current will pass through the primary 1, and only a corresponding number of waves will be generated in the secondary 33 and pass through-the X-ray tube 30. In other words, a current will be delivered to the X-ray tube equivathe position shown in' Fig. 4 at the zero value of the" wave, then upon rotating the shaft 6, ahalf wave will be fed over the wire 16 through the switch 4:8, and over the wire 18, through the contact 24, through the segment 8, and over the wire 17 back to the source of current during a quarter of a turn in each. revolution or until the edge 45 reaches the contact 24-. When this happens, however, the opposite edge of the segment 8 has reached the contact 22, and therefore, a half wave will also be fed through the wire 16 contact 22, segment 8 and over the wire 17 back to the source of current during still another quarter of a turn in each revolution. It thus results that when the edge 45 of the segment 8 is adjusted to the position shown in big. 4, two half waves of current will be sent through the X-ray tube 30 during a half turn of the disk 7, for each revolution and the equivalent of a 30 cycle current will be delivered to said X-ray tube. Again, if the switch 48 is made to contact with the pin 50, then current from the primary 1 will be short circuited from the wire 16 to the wire 17, and no current at all will pass through the contacts 22, 23 or 24, but the full 60 cycles will be delivered to the X-ray tube 30. It will now be clear that by the simple expedient of providing the shaft 6 of the m0- tor 2 with the disk 7 and conducting member 8 extending 180 around the circumference of said disk, I am enabled from a 60 cycle current to send the equivalent of a 15 cycle current, a 80 cycle current, or a 60 cycle current through the X-ray tube.

The special advantages of this device will be appreciated when it is said that by thus selecting every fourth half wave for revolutions and thus making the equivalent of 15 cycles of a 60 cycle current, having the strength of say two milliamperes, I can produce as good fluoroscopic effects as if I employed say fifteen milliamperes with the 60 cycle current, while the wear and tear on the X-ray tube is very much less. In fact, with this device a circuit is had which owing to the persistence of vision, the lag of the plates and possibly to other causes is exceedingly smooth, regular and certain in all its actions; and therefore the results attained have proved in practice to be equal in all respects to those produced by currents from a static machine. Further, the apparatus can and I prefer that it be so arranged that the selecting action will take place when the voltage of the half waves is at or near zero, so that all sparking is eliminated.

When employing small synchronous motors for this kind of work, the disk 7 is liable -to wabble and produce uneven effects, and inorder to avoid this objection, I have placed on the opposite side of said disk a segment 55 in all respects the duplicate of Segment 8, which acts as a counterbalance, 65 and therefore steadies the rotations of the disk 7 and produces a perfectly smooth operation. This counter-balance I regard as an important feature of the invention, because practice has shown that very much better results are attained with it than without it.

In order to readily adjust the disk 7 around the shaft 6, I preferably employ any suitable locking device, such as the set screw 56.

It is obvious that those skilled in the art may vary the details of construction as well as the arrangements of parts without departing from the spirit of my invention, and therefore, I do not wish to be limited to the above features, except as may be required by the claims.

What I claim is 1. In a device of the character described the combination of a source of alternating current; a circuit for said current; a translating device;,an interrupter in said circuit between said source and said translating device; means for operating said interrupter in synchronism with said source of current; and means whereby the relative duration of opening to closing of said circuit may be varied, while still maintaining the interruptions at'the zero value of thewaves, substantially as described.

In a device of the character described the combination of a source of alternating current; a'circuit for said current; a translating device; an interrupter in said circuit between saidsource and said translating device, said interrupter being so adjusted as to open said circuit when certain predetermined waves have their Zero value; means for operating said interrupter in synchronism with said source of current; and means whereby the relative duration of opening to closing of said circuit may be varied, while still maintaining the interruption at the zero value of the waves, substantially as described.

3. In a device of the character described the combination of a source of current waves; a circuit for said source; a translating device a rotating member provided with a conducting element extending a predetermined angular distance around its path of rotation; and a plurality of members in said circuit adapted to simultaneously contact with said element for a predetermined interval during each'rotation, said conducting element being so adjusted that the circuit will be broken when certain predetermined w ves have their zero value and having a sulficient angular extent to permit a plurality of waves to pass during each interval of contact, substantially as described.

4. In adevice of the character described the combination of a source of current waves; a circuit for said source; a rotating member provided with a conducting element extending a predetermined angular.

distance around its path of rotation; a plurality of members in said circuit adapted to simultaneously contact with sa1d element for a predetermined interval during each primary coil in said circuit between said contact members and said source; a secondary coil associated with said primary .coil; and a translating device connected to said secondary coil, substantially as described.

' 5. In a device of the character described the combination of a source of current waves; a circuit therefor; a primary coil insaid circuit; a secondary coil associated with said primary coil; a rotating conducting element of a predetermined angular extent; a plurality of contact members adapted to simultaneously contact with said element for a predetermined in'ter'val during each rotation; means for including different pairs of said contact members in said circuit at will; and adevice adapted to receive current connected to said secondary coil, substantially as described,

6. In 'a device of the character described, the combination of a sourcev of current waves; a circuit for said waves; a primary coil in said circuit; a secondary coil associated with said primary coil; a rotating conducting segment of a predetermined angular extent; a motor shaft on which said segment is mounted; a plurality of contact members in said circuit adapted to contact with said segment for a predetermined interval during each rotation, said segment being so adj'us'ted that one of said contact members will break the circuit when certain predetermined waves have their zero value; a switch member for connecting diflerent contact members in circuit; and a device adapted to receive current connected to said secondary coil, substantially as described.

7. In a device of the character described, the combination of a source of current waves; a primary coil; a secondary coil associated with said primary coil; a rotating conducting segment of a predetermined angular extent; a rotary'member on which said se ment is mounted; a counterbalance on sai member, a' motor shaft on which said member is mounted; a plurality of contact members adapted to contact with said segment for a predetermined interval during each rotation; connections between one of said contact members and'said primary coil; connections between another contact member and said source; a switch member for connecting different contact members in pairs; and a device adapted to receive current connected to said secondary coil: substantially as described. a

8. The method of causing a current of waves of a given frequency to have the effects in a translating device of a plurality of currents of lesser frequencies, which consists supplying current waves of a predetermined frequency per second to a cir- -cuit; cutting out for each current the effect of which it is desired to produce, a different predetermined plurality of said waves at predetermined intervals during each second; and passing during each second through said translating device Waves corresponding to those not cut out, substantially as described.

In testimony whereof, I 'aflix my signature, in presence of two Witnesses.

HARRY F. WAITE.

Witnesses:

Enw. A. DoUN, HARRY GELOHTER. 

